A study in the Philippines has found the number of teenage girls who have become pregnant across the nation has more than doubled in ten years.

According to the latest Young Adult Fertility and Sexuality (YAFS) study, around 14 per cent of girls aged 15 to 19 are either pregnant for the first time or are already mothers.

That is up from about six per cent recorded by an earlier YAFS study in 2002.

YAFS study coordinator and director of the University of the Philippines Population Institute, Josefina Natividad, has told Radio Australia's Asia Pacific Program a lack of awareness of the consequences of risky sexual behaviour is contributing to the rising rates of teenage pregnancies.

"I think that the very high level of teenage pregnancy points to the big gap between the behaviours of young people and the consequences of those behaviours," Professor Natividad said.

"Our findings would be supportive of the idea that we should really be improving on sexuality education for young people and then maybe providing them with the services that they need in order to protect themselves from unwanted consequences of sexual behaviour."

The nationwide study also shows one in three youth between the ages of 15 and 24 are having sexual intercourse before marriage, compared to 23 per cent a decade ago.

But while young people appear to be getting more sexually active in the predominantly Catholic nation, 78 per cent of the youth surveyed are not using any form of contraception or protection against sexually transmitted diseases when they are having sex for the first time.

Limited access

Professor Natividad says young people in the Philippines have limited access to sex education and sexual health services, especially if they are underage and unmarried, due to ongoing objections from the Catholic Church.

"We are a very conservative society and there is a lot of opposition from the Catholic Church about the open use or advocating safe sex among young children because the belief is that this is against morality," she said.

"While maybe young people are changing in their behaviours, there is no corresponding education about how they should protect themselves from the consequences of the activity."

Philippine president Benigno Aquino signed the Responsible Parenthood and Reproductive Health Act, widely known as the Reproductive Health Law, in 2012 to make sexual health services are more accessible and to ensure mandatory sex education.

However, the country's Supreme Court has delayed its implementation with a temporary restraining order, after members of the Catholic church and pro-life groups filed petitions against the law.

Professor Natividad says it is extremely difficult to implement formal sex education programs in the country.

"It is very much a challenge...because of the very strong Catholic lobby," she said.

"One year after the [Reproductive Health Law] was signed, it still hasn't been fully implemented because there's a very strong opposition."

The Supreme Court's ruling on the law is now expected in April.

New technologies

Meanwhile, the nation's youth are becoming increasingly active on the internet and their smartphones.

According to the study, one in four young people have sent or received sexually explicit videos through their mobile phone or the internet, and four per cent have directly met their sexual partners online or through text messaging.

"We suspect that the change in the form of influences, they affected in many ways, the way that they deal with one another now with regards to sexual behaviour," Professor Natividad said.

"We have found, for example, that there's quite a number that would have met sexual partners through these new technologies, either through the internet or via the cell phone. So these are new ways of connecting that were not there before."

Peer education showing potential

Professor Natividad says young people are also largely influenced by their peers and this could be key to raising awareness about safe sex outside of formal sex education programs.

"There is a lot of non-governmental work going on that is trying to engage young people," she said.

"It seems like young people will listen to people of their own age.

"The survey is also showing that if the young people have questions about sex, the people they will tend to turn to would be their friends.

"So if we have programs on peer education, that is probably one way of reaching these young people, by having people their own age be the advocates for change."